1. Field of the Invention
This invention relates to a storage condition controller and more particularly to a storage condition controller for monitoring and controlling a singular and/or multiple compartments in a refrigerator. The storage condition controller of this invention is also capable of storing food at optimum temperature based upon predetermined preferred storage temperatures for different foods or food groups.
2. Discussion of the Prior Art
It has long been known that chilling or freezing will aid in the preservation of food products. Recently it has been shown that storing some food products within a critical temperature range can more effectively keep harmful organisms from growing and multiplying. One such organism is a food born bacteria called Listeria monocytogenes that can cause serious illness. Ingestion of Listeria and other harmful organisms have resulted in illness and even the death of many people in the United States every year. It has been found that the risk of illness caused by Listeria and/or other harmful organisms can be reduced by rapid chilling and storing food products at a temperature between 32-40xc2x0 F.
Furthermore, the Food Safety and Inspection Service of the United States Department of Agriculture reminds consumers who are at risk from illness of Listeria and/or other food borne illnesses to take extra precautions when eating certain foods including ready-to-eat foods such as lunch meat and hot dogs. One of the recommendations is to refrigerate or freeze unconsumed perishable foods within two hours of preparation and to keep foods at risk refrigerated at or below 40xc2x0 F. if fresh or frozen at 0xc2x0 F. or below.
On the other hand, although storing many food products in refrigerated compartments will prolong the food""s usable life, excessive chilling of some fruits may cause injury and hasten spoilage. The critical temperature at which chilling injury occurs for many fruits is around 50xc2x0 F. At that temperature, bananas will become brown stained when refrigerated for about 8 hours. Likewise, a peach chilled in the range of 34-45xc2x0 F. will become mealy and brown within a short period of time. However, a peach may be stored successfully for several weeks by cooling it rapidly to approximately 32xc2x0 F. and closely maintaining that temperature.
In particular, regarding optimal storage temperatures for various food products, Food Science Australia, a joint venture of the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and the Australian Food Industry Science Centre (AFISC), identifies the following optimum storage temperatures of various food products:
Accordingly, it would be desirable to have a refrigeration unit having one or more compartments or chambers and furthermore, a refrigerator unit having multiple fresh food compartments whereby the temperature in each compartment may be monitored and maintained independently so as to be able to store each food product at its optimum storage temperature. In addition, it would be desirable to have a refrigeration unit having an electronic display of the actual temperature and elected temperature setting for each of said compartments. Furthermore, it would be desirable to have a refrigeration unit having a programmable electronic circuit wherein a temperature range or setting for each compartment is programmed by using a display panel with input functions to select or enter the food product that is to be stored in the compartment. A number of preprogrammed settings would be preset at the factory; however, an operator or user of the refrigeration unit should be able to alter the program for the temperature setting of a food product or add temperature settings for additional food products as may be desired.
Lastly, it would be desirable to have a refrigeration unit wherein preprogrammed electronic circuitry could be used to set and monitor other conditions in the storage compartments such as humidity, air movement, light or radiant energy or any other condition desired or required to be set or displayed. It would be most convenient if the aforementioned displays and settings were available for view and setting on the exterior of the refrigerator for convenience, observation and setting of the storage compartment conditions without need to open the door of the refrigeration unit, thus conserving energy and assisting in maintaining optimum storage conditions.
Heretofore, it has been known to provide a refrigerator having multiple compartments or chambers and to provide varying temperatures in each of said compartments, including multiple compartments in the temperature ranges for fresh food. Such a refrigerator is disclosed in U.S. Pat. No. 2,986,009, to J. Gaysowski, incorporated herein by reference. The refrigerator in Gaysowski is configured with five vertically stacked compartments with each compartment being maintained at a different temperature range. The lowest compartment is designed to operate at a temperature range of 0-10xc2x0 F. with the other compartments operating in the ranges of 10-20xc2x0 F., 20-30xc2x0 F., 30-40xc2x0 F., and 40-60xc2x0 F. in order of vertical ascensi refrigerator in Gaysowski attempts to maintain the desired temperature range in each compartment or chamber by using only one temperature monitoring thermistor located in the middle chamber and a single variable resistor control coupled to the chilling unit for raising or lowering the overall temperature to be maintained inside the refrigerator.
The temperature variance in the chambers of the refrigerator in Gaysowski is achieved by using panels/piles of different sizes located at the top of each chamber such that each pile includes a different number of thermocouples. The chamber with the coldest desired temperature has the smallest pile located at the top thereof having the least number of thermocouples. To correspond with the desired increase in temperature range in each ascending chamber, each consecutive pile has an increased size and number of thermocouples so that the pile at the top of the chamber with the highest temperature setting has the largest pile and most thermocouples. The piles having more thermocouples are capable of transferring more heat thereby maintaining different temperature ranges in each chamber. The refrigerator in the Gaysowski patent does not provide a means of individually displaying, monitoring, setting, or adjusting the temperature in each chamber.
It is also been known to provide a refrigeration unit having a temperature gauge and a thermostatic control on the exterior of the refrigerator, and furthermore to have separate temperature gauges and thermostatic controls for the freezer compartment and the fresh food compartment, such as disclosed in U.S. Pat. Nos. 4,014,178 and 4,148,194 to J. Kells, both incorporated herein by reference. However, the refrigerators in the patents to Kells do not offer programmable electronic circuitry for setting, monitoring and displaying the temperature in each compartment, and furthermore, the patents to Kells do not recognize the need for more than one fresh food compartment, and more particularly, the need for multiple fresh food compartments having individual monitoring and temperature control.
It is also known to put an electronic temperature display and control on the exterior of a specimen transporter as disclosed in U.S. Pat No. 5,483,799 to M. Dalto, incorporated herein by reference. The temperature control module in the Dalto patent can be used to set and store the minimum and maximum desired temperatures in the transporter""s memory circuit. The temperature control module also displays the current operational status of the storage compartment. The temperature control mechanism used in the Dalto patent includes a temperature probe for sensing the temperature and a means to activate the heating or cooling functions of the unit to maintain the temperature between the minimum and maximum set temperatures. The patent to Dalto does not disclose multiple compartments or the capability of programming the transporter temperature by inputting the type of product to be stored therein.
A mechanism for controlling the temperature of a fresh food refrigerator compartment utilizing air flow from the freezer compartment is disclosed in U.S. Pat No. 5,901,562 to S. Tunzi et al, incorporated herein by reference. The Tunzi invention utilizes manual controls of the rack and pinion type to alter the air flow characteristics. Other methods of altering the temperature and air flow of a chamber in a refrigeration unit are disclosed in U.S. Pat No. 4,358,932 to R. Helfrich, Jr., U.S. Pat. No. 4,858,443 to K. Denpou, and in 5,931,010 to J. Kim, all incorporated herein by reference and all of which relate to quick chilling chambers that are not designed to maintain food products within their optimum temperature range.
Lastly in U.S. Pat. No. 2,368,294 to W. Giffard incorporated herein by reference, a refrigerator unit is disclosed having one freezer compartment and two fresh food compartments whereby one fresh food compartment is cooled by convection currents from the primary evaporating element which condenses moisture from the air in the compartment to provide a low moisture environment. The other fresh food compartment is maintained at a high humidity level by limiting the circulation of air between said compartment and the primary evaporating element. The patent to Giffard does not possess an electronic control to display, monitor and/or adjust the humidity levels in the compartments.
None of the above references disclose or suggest a refrigeration unit having multiple fresh food compartments whereby the temperature may be electronically monitored and maintained independently for each compartment. Furthermore, none of the references disclose programmable electronic circuitry whereupon the temperature setting or range of the compartment may be set and maintained by selecting the food product to be stored therein.
It is a feature of the invention to provide a refrigerator having one or more compartments. The refrigerator has a housing, a cooling mechanism contained in the housing, and a storage condition controller including programmable electronic circuitry for controlling storage conditions within the refrigerator and an electronic display capable of displaying the temperature of each of said compartments.
Another feature of the invention is that the display on the refrigerator may depict the humidity level and air movement, for at least one of said compartments.
It is also a feature of the invention that the programmable electronic circuitry includes memory circuitry containing preprogrammed optimal storage conditions for the preservation of numerous food products and wherein the display depicts the optimum storage conditions including the optimum temperature for preservation of various food products or food groups.
It is a further feature of the invention that an operator may program the electronic circuitry to include preservation conditions including temperature for additional food products and change the preprogrammed settings.
Another feature of the invention is that the cooling mechanism includes individually controllable evaporator sections or other heat management systems in each of said compartments.
Lastly, it is a feature of the invention that the storage condition controller includes at least one temperature sensor in each of said compartments for sensing the temperature therein, said temperature sensors being electrically connected to an externally visible control module and said programmable electronic circuitry contained within said module, and an input control for inputting a temperature range setting for each of said compartments and whereas the control module is electrically connected to the cooling mechanism for activating and deactivating the mechanism to maintain the temperature of each compartment in accordance with the input settings.